Participants received a monetary reward. Procedures were approved by the local Psychology ethics committee. Laboratory

apparatus comprised an Apple Mac Mini, with Labtec speakers positioned either side of a 17″” Sony HMD-A420 cathode ray tube (CRT) display, viewed in darkness from 70 cm. Mobile apparatus for older participants and PH comprised a Sony Vaio SZ1XP PC with built-in speakers Bcl-2 inhibitor and 13.3″” liquid crystal display (LCD) display, viewed from approximately 57 cm. In both cases video mode was 1200 × 800 with a 60 Hz refresh rate. Subjects responded using the cursor keys on the standard keyboard. McGurk stimuli were based on Soto-Faraco and Alsius (2007), which were kindly provided by the authors (see Fig. 2 for dimensions, and Video 1 and Video 2). Auditory /ba/ and /da/ phonemes (with white noise at 15% of maximum

amplitude) were combined with visual lip-movements for [ba], [da] and [ga]. The two incongruent pairings for eliciting the McGurk effect were /ba/ + [ga] = ‘da’ and /da/ + [ba] = ‘ba’ or ‘bda’. The other two ‘congruent’ pairings /ba/ + [ba] and /da/ + [da] tend to be heard correctly. Background was set to the average red green blue (RGB) value across all pixels and frames. For the Selleckchem ZVADFMK Stream–Bounce experiment, visual stimuli were two yellow circular at maximum contrast on a black background. Each moved from positions left and right above fixation, via the central fixation point, to opposite positions below fixation (see Fig. 2 for dimensions, and Video 1 and Video 2). Animations were accompanied by a 400 Hz tone of 100 msec duration, with the same manipulation Exoribonuclease of asynchrony

as for the McGurk stimuli. Movies were followed by 9 pt white text prompting responses, displayed centrally. The following are the supplementary videos related to this article: To view the video inline, enable JavaScript on your browser. However, you can download and view the video by clicking on the icon below Video 1.   McGurk stimulus demo: Four combinations, played consecutively: 1. Auditory /ba/ with visual [ba]: congruent. 2. Auditory /ba/ with visual [ga] (incongruent: McGurk effect sounds like “da”). 3. Auditory /da/ with visual [ba] (incongruent: McGurk effect sounds like “ba”). 4. Auditory /da/ with visual [da]: congruent. We also tested PH with various biological and/or non-speech stimuli. Finger-click movies, of 3000 msec duration, showed a hand with the middle finger clicking against the thumb. Sequences began with either the hand open (to provide predictive information) or closed. For scrambled-speech stimuli, the soundtrack from the original McGurk stimuli was passed through a three-channel noise vocoder using Praat software (version 5.1.21, http://www.praat.org), rendering the speech unintelligible but without affecting the spectral composition of the sound or the temporal sequence of amplitude modulations. The video sequence remained the same. Non-biological stimuli comprised a white square (1.